A locking device for locking the steering column of a vehicle is a standard feature on virtually all modern automobiles. For safety reasons, it is important that a vehicle's steering column locking device operate so that in the event of a simple failure, be it software or material, the device under no circumstances will cause an accidental locking of the steering column while the vehicle is in motion. Systems are therefore designed as a safety feature to prevent the unintended locking of the steering column.
Conventional systems for preventing unwanted locking of a steering column use two electronic microcontrollers operating in tandem. The microcontrollers monitor each other so as to prevent electrical, software, mechanical or other failures from causing an accidental locking of the steering column. Such a solution is described in European Patent No. 496,509 A1 filed in the name of Lucas Industries Public Limited Company in connection with an electronic calculator for an ABS wheel anti-locking system.
The main drawback of such a system, however, is its high cost. Not only must the microcontroller be duplicated, but also its clock and reset circuit. Accordingly, there is the need for a system that can effectively prevent the unwanted locking of a steering column, but that is more efficient than conventional systems.